package com.interviews.prodconsumer;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * 传统版
 * 题目：一个初始值为零的变量，两个线程对其交替操作，一个加1一个减1 来5轮
 * 1    线程      操作      资源类
 * 2    判断      干活      通知
 * 3    防治虚假唤醒机制
 *
 * @author qian
 * @version 1.0
 * @date 2022/2/23 14:11
 */
public class TraditionDemo {

    public static void main(String[] args) {
        ShareData shareData = new ShareData();


        new Thread(() -> {
            for (int i = 0; i < 5; i++) {

                try {
                    shareData.increment();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }, "AA").start();

        new Thread(() -> {
            try {
                for (int i = 0; i < 5; i++) {
                    shareData.decrement();
                }

            } catch (Exception e) {
                e.printStackTrace();
            }
        }, "BB").start();
    }
}


class ShareData {

    private int number = 0;
    private Lock lock = new ReentrantLock();
    private Condition condition = lock.newCondition();

    public void increment() throws Exception {
        lock.lock();
        try {
            // 判断
            while (number != 0) {
                // 等待，不能生产
                condition.await();
            }
            // 干活
            number++;
            System.out.println(Thread.currentThread().getName() + "\t" + number);
            // 通知唤醒
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }


    public void decrement() throws Exception {
        lock.lock();
        try {
            // 判断
            while (number == 0) {
                // 等待，不能生产
                condition.await();
            }
            // 干活
            number--;
            System.out.println(Thread.currentThread().getName() + "\t" + number);
            // 通知唤醒
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }
}
